Chicken eggshells are made to protect the yolk and white inside. They are made out of 95% Calcium Carbonate (CaCO3), and about 5% of a protein matrix. The eggs have over 9,000 pores that allow the eggs to breathe, and to allow for the carbon dioxide to escape. One thing that effects the strength of an egg shell the most is the health and nutrition of the chicken that laid it. If a chicken is unhealthy, then it may lay an egg that has no shell, or has a thin soft shell, like a turtle egg. In structure, an eggshell is two domes, one on top of the other. The reason that eggshells are actually quite strong is that if force is applied to one point on the egg, that the force will be distributed across the whole dome. An eggshell is weakest if it is rapped in one spot, instead of force building up over time. The force applied to the egg creates compression on the inside of the egg and tension on the inside. All of these reasons mean that an egg as a whole is much stronger than the pieces by themselves. This makes most eggshells eggcedelingly strong, given their light weight.
Procedure
We blew out all 2 1/2 dozen of each type. We accidentally cracked about 10 eggs, but we saved them as our practice eggs. We proceeded to freeze 7, boil 7, and leave 7 at room temperature of each kind. We performed these actions on 7, even though we were only testing 5 because we assumed that some eggs would crack in the preparation process. We taped 8 pencils, evenly spaced, to the top of a 1000 mL beaker with their points up. We placed the ring on the ring stand at a height which allowed the beaker to sit on top of the egg, while the pencils encircled the ring stand so that the beaker wouldn’t fall. We then placed a 500g weight in the bottom of the beaker, and then set the beaker on top of the egg. We added sand to the beaker until the egg was crushed, while gently tapping the bottom of the beaker, and then recorded the weight necessary to crush the egg in our results. To keep the beaker from breaking, we placed a clay ring outside the egg so that the beaker would land on the ring instead of on the hard metal ring stand. We made the clay ring large enough so that the eggshell would not touch it, because this would interfere with our measurements.
Results
Eggshell Strength Experiment
Frozen Eggs
test #
Brown Eggs
White Eggs
1
1772.97g
1
1854.17g
2
1869.85g
2
1815.02g
3
1239.95
3
2397.01g
4
2090.00g
4
1637.18g
5
2049.11g
5
2029.12g
Average:
1804.38g
Average:
1946.50g
T-Test:
p=.4972
Room
Temperature
Eggs
test #
Brown Eggs
White Eggs
1
2427.70g
1
2470.49g
2
2067.35g
2
1890.60g
3
1256.19g
3
2270.00g
4
1918.03g
4
2095.59g
5
1709.29
5
1555.46g
Average:
1875.71g
Average:
2056.43g
T-Test:
p=.4922
Boiled Eggs
test #
Brown Eggs
White Eggs
1
1898.04g
1
1283.01g
2
1511.67g
2
2422.71
3
1691.72g
3
1616.52
4
2053.58g
4
1204.63g
5
1619.73g
5
1872.88g
Average:
1754.95g
Average:
1679.95g
T-Test:
p=.7677
After we completed our analysis section, we found that white eggshells are equivalent to brown eggshells in strength. This allowed us to pool all of our measurements for for brown and white eggshells for frozen, room temperature, and boiled eggshells. We did more T-Tests to determine if there was any statistical significance between the treatments the eggs had received. For the Frozen-Room Temperature T-Test, our p-value was .5680, and the average strengths for frozen and room temperature eggs were 1875.44g and 1966.07g, respectively. For the Frozen-Boiled T-Test, we had a p-value of .3070, with averages for frozen and boiled at
1875.44g and 1717.45g respectively. For the Room Temperature-Boiled T-Test, the p-value was .1543, and the averages were 1996.07g, and 1717.45g, respectively.
Analysis
When comparing white and brown eggs, we found that with changing conditions, there is no significant difference between the strengths of the different eggshells. With a p-value of .4972, .4922, .7677 for Frozen, Room Temperature, and Boiled Eggs respectively, there was no statistical difference between the two types of eggs. Although White Eggshells seems slightly stronger on average in two of the three tests (Frozen and Room Temperature Tests), the Brown Eggshells were stronger in the remaining test (Boiled Test).
Conclusions
Through our experiments with white and brown eggs, we found that there is no notable difference between the eggshells of the two different colors. Though the white eggs showed a slightly higher average in two of the tests, the range of the data did not present a significant difference from that of the brown eggs. Because there was such variation in the maximum possible weight held by each eggshell it is difficult to find any trends in the data. The research that we found on multiple web sites indicates that more than the color of the egg, the nutrition of the mother directly affects the strength and composition of the eggshell, which would support our conclusion ( Evanhoe, n.p.). When we performed the T-Tests for the different treatments on the eggs, there was not a statistical difference between the two sets, but as the p-value got closer to zero, the difference in averages did, as well. The test with the lowest p-value, the Room Temperature-Boiled Eggshells test gave us a p-value of .1543, and a difference in averages of 278.62, which was by far the largest difference between two sample sets. There are a few ways that this experiment could be improved. One of them is to use a drill press to drill the holes in the eggs so that there is a constant hole size. When drilling by hand, hairline cracks often appear around the hole, an this leads to weakening of the egg. Also, a different system to hold the beaker upright would be helpful.
Eggshell Strength Experiment Lab Report
Emma, Colin
Table of Contents
Introduction
Chicken eggshells are made to protect the yolk and white inside. They are made out of 95% Calcium Carbonate (CaCO3), and about 5% of a protein matrix. The eggs have over 9,000 pores that allow the eggs to breathe, and to allow for the carbon dioxide to escape. One thing that effects the strength of an egg shell the most is the health and nutrition of the chicken that laid it. If a chicken is unhealthy, then it may lay an egg that has no shell, or has a thin soft shell, like a turtle egg. In structure, an eggshell is two domes, one on top of the other. The reason that eggshells are actually quite strong is that if force is applied to one point on the egg, that the force will be distributed across the whole dome. An eggshell is weakest if it is rapped in one spot, instead of force building up over time. The force applied to the egg creates compression on the inside of the egg and tension on the inside. All of these reasons mean that an egg as a whole is much stronger than the pieces by themselves. This makes most eggshells eggcedelingly strong, given their light weight.
Procedure
We blew out all 2 1/2 dozen of each type. We accidentally cracked about 10 eggs, but we saved them as our practice eggs. We proceeded to freeze 7, boil 7, and leave 7 at room temperature of each kind. We performed these actions on 7, even though we were only testing 5 because we assumed that some eggs would crack in the preparation process. We taped 8 pencils, evenly spaced, to the top of a 1000 mL beaker with their points up. We placed the ring on the ring stand at a height which allowed the beaker to sit on top of the egg, while the pencils encircled the ring stand so that the beaker wouldn’t fall. We then placed a 500g weight in the bottom of the beaker, and then set the beaker on top of the egg. We added sand to the beaker until the egg was crushed, while gently tapping the bottom of the beaker, and then recorded the weight necessary to crush the egg in our results. To keep the beaker from breaking, we placed a clay ring outside the egg so that the beaker would land on the ring instead of on the hard metal ring stand. We made the clay ring large enough so that the eggshell would not touch it, because this would interfere with our measurements.
Results
After we completed our analysis section, we found that white eggshells are equivalent to brown eggshells in strength. This allowed us to pool all of our measurements for for brown and white eggshells for frozen, room temperature, and boiled eggshells. We did more T-Tests to determine if there was any statistical significance between the treatments the eggs had received. For the Frozen-Room Temperature T-Test, our p-value was .5680, and the average strengths for frozen and room temperature eggs were 1875.44g and 1966.07g, respectively. For the Frozen-Boiled T-Test, we had a p-value of .3070, with averages for frozen and boiled at
1875.44g and 1717.45g respectively. For the Room Temperature-Boiled T-Test, the p-value was .1543, and the averages were 1996.07g, and 1717.45g, respectively.
Analysis
When comparing white and brown eggs, we found that with changing conditions, there is no significant difference between the strengths of the different eggshells. With a p-value of .4972, .4922, .7677 for Frozen, Room Temperature, and Boiled Eggs respectively, there was no statistical difference between the two types of eggs. Although White Eggshells seems slightly stronger on average in two of the three tests (Frozen and Room Temperature Tests), the Brown Eggshells were stronger in the remaining test (Boiled Test).
Conclusions
Through our experiments with white and brown eggs, we found that there is no notable difference between the eggshells of the two different colors. Though the white eggs showed a slightly higher average in two of the tests, the range of the data did not present a significant difference from that of the brown eggs. Because there was such variation in the maximum possible weight held by each eggshell it is difficult to find any trends in the data. The research that we found on multiple web sites indicates that more than the color of the egg, the nutrition of the mother directly affects the strength and composition of the eggshell, which would support our conclusion ( Evanhoe, n.p.). When we performed the T-Tests for the different treatments on the eggs, there was not a statistical difference between the two sets, but as the p-value got closer to zero, the difference in averages did, as well. The test with the lowest p-value, the Room Temperature-Boiled Eggshells test gave us a p-value of .1543, and a difference in averages of 278.62, which was by far the largest difference between two sample sets. There are a few ways that this experiment could be improved. One of them is to use a drill press to drill the holes in the eggs so that there is a constant hole size. When drilling by hand, hairline cracks often appear around the hole, an this leads to weakening of the egg. Also, a different system to hold the beaker upright would be helpful.
References
Butcher, Dr. Gary D. and Dr. Richard D. Miles. "Concepts of Eggshell Equality." 25 Jan. 2010. Web. <http://www.webcitation.org/5mreqG0IM>.
Evanhoe, Rebecca. "Chicken Eggs." 22 Jan. 2010. Web. <http://pubs.acs.org/cen/whatstuff/84/8434egg.html>.
LeDuff, Peggy and Nabila Jachan. "Eggshell Dome Discrepant Event." 31 Jan. 2010. Web. <http://www.csun.edu/~mk411573/discrepant/
discrepant_event.html>.
Wikipedia. "Eggshell." 26 Jan. 2010. Web. <http://en.wikipedia.org/wiki/Eggshell>.